An expert would tell the court the level of morphine found in the 63-year-old's system was the equivalent of him taking 20, 100-milligram tablets.

Ms Telfer told the jury that after the death of Mr Lawrence, Dent, who was brought from Dapto in NSW to face trial, had tried to portray their relationship in such a way as to maximise her chances of benefiting financially.

But in an opening statement, defence counsel Stephen Apps told the jury Dent had shared her own medication with Mr Lawrence at his request to help ease his back pain.

Mr Apps said the defence would submit that Mr Lawrence died from an accidental overdose.